Flexible bands fitted with hooks for the fabrication of separable fastening devices

ABSTRACT

A flexible band having hooks formed of threads of thermoplastic material for engagement with a similar flexible band having elements adapted to cooperate with said hooks so as to constitute a separable fastening device, in which the hooks are obtained by cutting one of the two loop arms of thermoplastic threads, the cutting operation being carried out at a predetermined distance from the crest of each loop. A terminal enlargement is essentially formed on at least one of the two thread extremities which result from the cutting operation.

l will States Patent 1 Jan. 15, 1974 illarant 24/204 lkoma et 24/204 RXCU 54 r m mm 8 mm 380 2577 www WUUfl 6737 720 00226 9 0 0 7 5257 4855 2313 SE KL 08 0A R A HP TE IS WF 0 E Tm TIS TE AC S I. mam ABD BMG E NLEI BH IMTE X T ma FF 4 U.

[75] Inventor: Patrick Billarant, Nantes, France [73] Ass1gnee: VelcoFrance, Pans, France Primary Examiner-Donald A. Griffin Filed: Sept. 1,1971 Att0rney-Ostrolenk, Faber, Gerb & Soffen [2i] Appl. No.: 177,118

Related US. Application Data ABSTRACT [62] Division of Ser. No. 88l,533,Dec. 2, 1969, Pat. No.

fr 0 m m .m mu h h I f-l o w dt m m m n we m f .m a v .1 a m n m m m S mm m w X e m m Am [30] Foreign Application Priority Data Dec. 13, l968flexible band having elements adapted to cooperate a separable fasten-France............................ 68.176343 with said hooks so as toconstitute ed nhe ntne m m M mam ye b mm d m w e f .m A a 20 12 60 79 /3m n w W 1 m; 0 R4 w ooA 9 8 6 a ZMMR 4 W2 03M 2 /d 43 D 2 m u m s, n.mmm2 m mmm nus he y "88 .L -M C I 6 S k UImF MUN 555 [56] ReferencesCited UNITED STATES PATENTS l,3|4,747 9/1919 Hodges.................24/230.5 CR UX 4 Claims, 5 Drawing Figures PATENTEUJAM 15 1974 saw 1 I)?2 I FLEXIBLE BANDS FITTED WITH HOOKS FOR THE FABRICATION OF SEPARABLEFASTENING DEVICES This application is a division of application Ser. No.881,533 filed Dec. 2, 1969, and now U.S. Pat. No. 3,673,301 issued June27, 1972.

The present invention relates to flexible bands which are provided withhooks formed of thermoplastic material and which are intended to beutilized in conjunction with bands provided with elements adapted tocooperate with said hooks, thereby constituting separable fasteningmeans such as devices of the type which provide instantaneous engagementand release for purposes of closure or attachment.

This invention is more particularly concerned with bands of the typementioned above in which said hooks are obtained by cutting one of thetwo arms of loops of threads of thermoplastic material, this cuttingoperation being carried out at a predetermined distance from the crestof each loop.

The invention applies not only to bands of the type in which the hooksare embedded in a sole or base sheet of plastic material but also to allbands or strips fitted with hooks, irrespective of the modes offormation and attachment of said hooks, whether such hooks are obtained,for example, by cutting the loops of a woven product or by molding so asto be integral with the band or plate.

The object of the invention is to enhance the gripping power", orcapacity of the flexible bands for secure attachment to the similarbands with which they are associated.

With this objective, in an improved flexible band according to theinvention, provision is made for a terminal enlargement on at least oneof the two thread extremities formed by cutting one arm of a thread loopin order to form a hook.

In one embodiment in which said terminal enlargement is formed on thecurved portion of the hook, it is apparent that when a hook of this typeexerts a substantial effort on the element to which it is fastened, saidbook first opens and then carries out a sliding movement. However, priortofinal disengagement, the terminal enlargement of the hook grips saidelement, thereby extending the retaining action of the hook andconsiderably increasing the gripping power of the separable fasteningdevice which is provided with hooks of this type.

In another embodiment, provision is made not only for a terminalenlargement on the curved portion of the hook but also for an additionalterminal enlargement on the cut portion of the loop arm which isembedded in and secured to the band. In this embodiment, each hook whosegripping power has already been considerably increased is duplicated bya second fastening element constituted by said cut portion of the looparm and terminal enlargement which is also adapted to engage with acorresponding element of an associated flexible band. In respect of agiven number of hooks, the band considered therefore has a number offastening elements which is double the number of hooks after elements.The result thereby achieved is a very considerable increase in thegripping power of the band which is treated in this manner.

Should it be desired to do so, it is also possible in accordance withthe invention to form bands in which an enlargement is not formed on thecurved extremity of each hook whereas provision is made for a terminalenlargement on the cut portion of loop arm which is secured to theflexible band. Alternatively, bands can be provided with hooks havingterminal enlargements whilst the cut projecting portion of loop which issecured to the band is of very short length and may even benon-existent.

The invention is also directed to a method whereby terminal enlargementsof the type referred-to are formed on the fastening elements of saidflexible bands.

This method consists in forming the terminal enlargement by means of anapplication of heat so as to cause partial melting of the threadextremity on which an enlargement is to be formed.

In one mode of operation, use is made of an electric heating resistorwhich is brought close to the thread extremity of the thread on which anenlargement is to be formed. In another mode of operation, a thin streamof air at a suitable temperature is directed onto the thread ofthermoplastic material on which it is desired to form a terminalenlargement. Thus, partial local melting of the thread is produced inboth modes of operation, thereby resulting in the natural formation of aballshaped terminal enlargement.

In one mode of execution which is adopted for the treatment of a band inwhich hooks have already been formed by cutting one of the two arms ofthread loops, a stream of hot air is directed onto the extremity of thecurved portion of the hook and/or onto the extremity of the cutprojecting portion of loop arm which is secured to the band.

In another mode of execution, a stream of hot air is directed onto oneof the two arms of thread loops at a predetermined distance from thecrest of each loop in order to carry out at the same time the cutting ofsaid loop arm for the purpose of forming a hook, the formation of aterminal enlargement on the curved extremity of the hook and theformation of a terminal enlargement on the portion of the loop arm whichis secured to the band.

Finally, the invention is concerned with means for carrying out themethod under consideration.

A device according to the invention comprises a rotary cylinder having arelatively small diameter in order to separate the fastening elements ofa flexible band which passes over said cylinder and a nozzle fordirecting hot air onto those parts of said elements on which a terminalenlargement is to be formed.

The invention is also concerned with embodiments which have at least oneof the following features a. the device which is intended to formterminal enlargements only on the cut projecting portions of thethread-loop arms which are secured to a flexible band on which the hookshave already been formed by cutting said loop arms comprises a freelyrotatable drum which is substantially tangent to said small-diametercylinder, longitudinal fins being provided on the periphery of said drumand shaped so as to penetrate in turn into the aforementioned cutsformed in the loops of the band which is driven in uniform motion onsaid cylinder, said drum being provided with longitudinal slits betweensaid fins in order to establish a temporary communication between a hotair discharge nozzle disposed on the inside of said drum and thecorresponding space formed between two fins, said fins being adapted toretain one or two of the aforementioned portions of loop arms which areto be provided in turn with a terminal enlargement.

b. The device which serves both to cut one threadloop arm and to form anenlargement on each of the two thread extremities thus formed comprisesa cap to which is imparted a radial movement with respect to theaforementioned small-diameter cylinder over which the band passes, alongitudinal channel for retaining a transverse row of loops beingformed in said cap and a duct connected to a source of hot air underpressure being adapted to open laterally into said channel, the periodicradial motion of the cap being carried out in synchronism with theforward motion of the band.

The invention is also concerned with separable fastening devicescomprising at least one band as defined in this Application.

A better understanding of the invention will be gained from thefollowing description, reference being made to the accompanying drawingsin which a few embodiments of the invention are shown by way ofnon-limitative example, and in which FIG. 1 is a sectional view on alarge scale showing a portion of a first embodiment of a flexible bandwhich is provided with improved fastening elements in accordance withthe invention;

FIG. 2 is a view of another embodiment;

FIG. 3 is a diagrammatic sectional view of a device for obtaining bandsof the same type as the band which is illustrated in FIG. 1;

FIG. 4 is a sectional view on a smaller scale and taken along line lV-IVof FIG. 3; and

FIG. 5 is a diagrammatic view of a device for obtaining bands of thetype illustrated in FIG. 2.

The flexible band, a portion of which is shown in FIG. 1, is constitutedby a sole or base sheet 1 of thermoplastic material, for example, inwhich are embedded the internal loops 2 located on one side of a layerof parallel undulated threads 3 which are also made of thermoplasticmaterial and the melting point of which is close to that of the basesheet 1. One arm of each of the loops of longitudinal threads is cut asshown at 5 at a given distance from the crests 6 of the undulations sothat the uncut arm 8 of each loop forms the stem of a hook whose curvedportion is constituted by the crest 6 of the wave and the portion 7which is adjacent to the cut 5. The cut extremity of the other arm 9 ofeach loop is provided with an enlarged portion 11 which hassubstantially the shape of a ball in the example shown in the drawings.Each terminal enlargement 11 of said band is therefore capable ofengaging in a corresponding element of a second band which is associatedwith the first, said element being either in the form ofa loop or, forexample, of transverse threads of an undulated system which is securedto a flexible base sheet. The first flexible band therefore has a totalnumber of fastening elements which is double the number of hooks.

In the alternative form which is illustrated in FIG. 2, the extremitiesof the curved portions 7 of the hooks also terminate in an enlargedportion 13 and this latter is also given the shape of a ball in theexample illustrated. These enlarged extremities serve to increase to avery substantial extent the gripping power or capacity of the hook 7 forsecure engagement with the elements of an associated band.

The device which is illustrated in FIG. 3 and 4 makes it possible toobtain the enlarged extremities 11 of the band which is illustrated inFIG. 1.

This apparatus comprises two horizontal cylinders 21, 22 which areprovided respectively with a fabric covering 23, 24 and over which ispassed a band 25 having a structure as illustrated in FIG. 1 except forthe fact that the loop-arm portions 9 have not yet been provided withterminal enlargements but are already separated from the portion 7 ofthe hook by the cut 5.

A roller 31 of relatively small diameter is mounted between the tworotary cylinders 21, 22 and at a lower level than these latter, theflexible band 25 being adapted to pass over said small roller in orderto ensure that the hooks should open out to a substantial extent as thesole or base sheet of said band is taken up by the cylinder 31 which hasa small radius of curvature, or in other words that the extremity 7 ofeach hook should move away from the extremity of the opposite arm 9which is joined to the base sheet as shown in FIG. 4.

The fabric coverings 23, 24 of the two cylinders 21, 22 serve to protectthe hooks as these latter pass over said cylinders since they arelocated on that side of the band which is in contact with saidcylinders.

A drum 34 which is substantially tangent to the smalldiameter roller 31is rigidly fixed to an end-plate 35 carried by a shaft 36 and thislatter is journalled in two bearings 37, 38 which are mounted in astationary support 39.

Fins 43 are fixed on the periphery of the drum 34 and are intended toengage between the stem of each hook and the arm of the loop in whichsaid hook has been formed and which is located opposite to the arm whichforms said stem.

In the embodiment which is illustrated, the hooks are placed back toback in pairs so that the two portions 9 of the arms of two successiveloops of longitudinal threads such as 3 are retained between two fins43. All the loops are aligned in the transverse direction so that thefins 43 extend over the entire width of the band 25 and retain acomplete row of loops.

The fins which are formed on the periphery of the drum therefore providea succession of chambers such as the chamber 45 which retain twoportions of arms such as the portion 9 and chambers such as the chamber46 in which corresponding hooks are received progressively as the bandmoves forward and is accompanied in its movement by the freely rotatingdrum.

Slits 48 extend over the entire width of the drum opposite to thechambers 45, thereby providing a communication between said chambers anda transverse nozzle 51 which is connected by means of a duct 52 to asource of air under pressure at a temperature which is sufficient toensure partial melting of the material of the arms 9 of the longitudinalthreads 3.

A nozzle 55 blows cold air onto the periphery of the drum 34 and thefins 43 in order to cool these latter and to prevent any damage to thehooks 7.

The operation takes place as follows at least the downstream cylinder 22is driven in the direction of the arrow fl so that the band 25 passesround the small-diameter roller 31 and is permitted by its hooks and bythe fins 43 of the drum 34 to drive this latter in the direction of thearrow f2. Each time two arms 9 are imprisoned within a chamber 45between two fins 43 of the drum and when the slit 48 of the drum passesin front of the nozzle 51, the hot air which is discharged through saidnozzle reaches the two extremities of said arms in a transient mannerand forms two substantially ball-shaped terminal enlargements 11 as aresult of partial melting of said extremities whilst the extremities ofthe hooks 7 which are protected by the fins against the action of thehot air remain intact. The band which is thus treated then passes overthe cylinder 22 and then has the appearance which is shown in FIG. 1.

In FIG. 5, there is shown diagrammatically another device for obtainingbands of the same type as those which are shown in FIG. 2. i

This device comprises two rotary cylinders which are identical to thecylinders 21, 22 of the embodiment of FIGS. 4 and 5 as well as asmall-diameter roller 31 over which the flexible band 65 passes. In thisexample, the

flexible band'is designed in the form of a sole 1 of thermo-plasticmaterial in which are embedded the undulations of one face of a layer ofparallel undulated threads 3 which consequently form closed loops 66 onthe other face.

A cap 71 is designed and arranged to move up against the small-diameterroller 31 and to move away from this latter periodically and insynchronism with the forward motion of the band 65 under the action ofany suitable mechanism such as the link-arm and crank system which isshown in the drawings. This system comprises an eccentric 73 which iscarried by a pin 74 and connected by means ofa link-arm 75 to the cap71, said cap being suitably guided as it carries out its radial movementwith respect to the roller 31 by any suitable means of conventional type(not shown in the drawings).

The cap 71 is provided with two channels 78, 79 in which two rows ofloops 66 of the band 65 are intended to fit exactly and in the mannerwhich is illustrated.

The cap 71 is provided with lateral ducts 81, 82 which are connected toa source of hot air under pressure and open into the two channels 78, 79respectively at a distance from the bottom of said channels whichcorresponds to the location at which one of the two arms of the twoloops 56 is to be cut as indicated at 5 in FIG. 2, the other arm ofthese two loops being applied againt a central rib 85 of the cap 71.

The operation of the device is as follows as the band 65 moves forwardand each time the cap 71 covers two rows of loops 66, the hot air whichflows through the ducts 81, 82 causes partial melting of one of the twoarms of each loop of the two transverse rows of loops considered,thereby cutting said arm so as to form a hook and forming at the sametime a terminal enlargement on each of the two resultant extremities ofthe cut thread, namely a terminal enlargement such as 13 which is formedon the curved extremity 7 of the hook and a terminal enlargement such as11 formed on the extremity of the arm 9 which is joined to the basesheet 1.

The ducts 81 and 82 are designed, for example, in the form of slitswhich extend over the entire width of the cap 71 or else only in theform of holes which open directly in front of each loop 66.

We claim:

1. A device for manufacturing a flexible band having undulatedorientated thermoplastic threads embedded by their roots in said bandand each undulating thread defining a hook and straight projection, thefree ends of each hook being directed toward said band and aligned withthe straight projections respectively, the facing free ends of each bookand of its associated straight projection being normally in closerelationship and at least one of the facing free ends provided with aterminal enlargement comprising a smooth, curved surface of smalldiameter adapted to receive and to longitudinally and resiliently bend aflexible band having undulated orientated thermoplastic threads embeddedby their roots therein to separate the threads from one another andmeans associated with said smooth, curved surface for directing hot airinto those parts of said threads on which a terminal enlargement is tobe formed.

2. The device of claim 1 wherein the smooth, curved surface is thesurface of a rotary cylinder having a small diameter.

3. The device of claim 2 wherein the means for directing hot aircomprises a freely rotatable drum positioned tangent to said smalldiameter cylinder, longitudinal fins on the periphery of said drum andshaped so as to pentrate cuts formed in said threads of said flexibleband, means for discharging hot air disposed within said drum, and hotair communication means between said means for hot air discharge andthose parts of said threads on which a terminal enlargement is to beformed through said drum.

4. The device of claim 2 wherein said means for directing hot aircomprises a cap member radially movable with respect to said smallcylinder over which the flexible band passes, a longitudinal channel forretaining a transverse row of said threads being formed in said capmember, means to impinge hot air laterally into said channel and onto alocal area of said thread loops, and means for the periodic radialmovement of said cap in synchronism with the motion of the flexible

1. A device for manufacturing a flexible band having undulatedorientated thermoplastic threads embedded by their roots in said bandand each undulating thread defining a hook and straight projection, thefree ends of each hook being directed toward said band and aligned withthe straight projections respectively, the facing free ends of each hookand of its associated straight projection being normally in closerelationship and at least one of the facing free ends provided with aterminal enlargement comprising a smooth, curved surface of smalldiameter adapted to receive and to longitudinally and resiliently bend aflexible band having undulated orientated thermoplastic threads embeddedby their roots therein to separate the threads from one another andmeans associated with said smooth, curved surface for directing hot airinto those parts of said threads on which a terminal enlargement is tobe formed.
 2. The device of claim 1 wherein the smooth, curved surfaceis the surface of a rotary cylinder having a small diameter.
 3. Thedevice of claim 2 wherein the means for directing hot air comprises afreely rotatable drum positioned tangent to said small diametercylinder, longitudinal fins on the periphery of said drum and shaped soas to penetrate cuts formed in said threads of said flexible band, meansfor discharging hot air disposed within said drum, and hot aircommunication means between said means for hot air discharge and thoseparts of said threads on which a terminal enlargement is to be formedthrough said drum.
 4. The device of claim 2 wherein said means fordirecting hot air comprises a cap member radially movable with respectto said small cylinder over which the flexible band passes, alongitudinal channel for retaining a transverse row of said threadsbeing formed in said cap member, means to impinge hot air laterally intosaid channel and onto a local area of said thread loops, and means forthe periodic radial movement of said cap in synchronism with the motionof the flexible band over said small diameter cylinder.